The goal of the proposed center is to address two fundamental questions about executive function: 1. What are the component mental processes that contribute to executive control? 2. How does the brain support and enable executive function? Executive function is a broad term that encompasses many critical skills and cognitive functions, including those that guide, control, inhibit, and monitor behavior. Because of its broad nature, there is no clear consensus on exactly what constitutes executive function, nor is there clear agreement on what neural, structures support executive control. In this proposal we argue that executive function is an emergent and modulatory function that represents an interaction among many different cognitive processes and also among many different brain regions. To investigate this issue we have organized the center around core processes that we posit contribute to executive function, as well as factors influencing the variability in executive function. The core processes are: (a) control processes, (b) learning processes, (c) memory retrieval processes, (d) emotional processes, and (e) language processes. We examine the first of these four processes each in a separate project, while the fifth, language processes, is examined across projects. We further posit that these processes co-contribute to executive function through their shared reliance on working memory and prefrontal cortex. The two sources of variability in executive function that we focus on are: (a) developmental variability and (b) genetic variability. To examine these issues, we have two projects that examine the development of executive function - one focused on childhood and the other focused on adolescence - and another project that examines genetic influences on executive function. The approaches taken within the center are highly interdisciplinary drawing from cognitive and clinical psychology, behavior genetics, cognitive neuroscience, physics, computer science, and child and adolescent development. Increased understanding of executive function is highly relevant for mental health, as aspects of it are compromised across a wide variety of psychiatric disorders, including schizophrenia, depression, mania, obsessive compulsive disorder, and attention deficit hyperactivity disorder, among others.